This invention relates to a new and improved hydraulic operated setting tool and liner hanger for securing a liner pipe string in a well bore preparatory to cementing the liner pipe string in place.
In the drilling or completion of wells, it is a common operation to set one or more liner hangers in a well. The liner hangers are attached to the upper end of a string of pipe and, when in position in a well, are set or anchored by mechanically or hydraulically operated mechanisms. A hydraulic, pressure set liner hanger has certain advantages in that it does not require mechanical movements of pipe and is, more or less, a positively set tool. In any hydraulically set mechanism for a liner hanger, it is, of course, desirable to reduce the possibility of fluid leaks in the liner hanger.
The present invention involves a hydraulically actuated setting tool and liner hanger which minimize the possibility of a malfunction or wrongful operation of the tool by only requiring one pressure operation for setting the liner hanger, and one operation for release of the setting tool from the liner hanger. The liner hanger is an integral member without ports and without special pressure sealing surfaces for the setting tool. All of the hydraulic pressure ports are in the setting tool so that the liner hanger is reduced to simply a body and slips. Since the entire setting tool can be retrieved, it is economical to recover the setting tool and service it. Also the setting tool and liner hanger are adaptable to re-working operations because the liner hanger has no specially ground surfaces.